Definition: In this task, you are given an input list A comprising of numbers and alphabets. You need to extract and sort the unique alphabets in the list. The alphabets in the input list will only be in lowercase. Return -1 if there is no alphabet in the input list.
Input: ['g', 'k', 'q', 'e', '9821', '8833', '9433', 'b']

b, e, g, k, q